/*
** $Id: lzio.h,v 1.31.1.1 2017/04/19 17:20:42 roberto Exp $
** Buffered streams
** See Copyright Notice in lua.h
*/

#ifndef lzio_h
#define lzio_h

#include "lua.h"

#include "lmem.h"

#define EOZ (-1) /* end of stream */

typedef struct Zio ZIO;

// Equals to this implement
// unsigned char zgetc(ZIO* z)
//{
//	int tmpNum = z->n;
//	z->n--;
//	if (tmpNum > 0) {
//		return *z->p++;
//	}else{
//		return luaZ_fill(z);
//	}
//}
#define zgetc(z) (((z)->n--) > 0 ? cast_uchar(*(z)->p++) : luaZ_fill(z))

typedef struct Mbuffer {
  char* buffer;
  size_t n;
  size_t buffsize;
} Mbuffer;

#define luaZ_initbuffer(L, buff) ((buff)->buffer = NULL, (buff)->buffsize = 0)

#define luaZ_buffer(buff) ((buff)->buffer)
#define luaZ_sizebuffer(buff) ((buff)->buffsize)
#define luaZ_bufflen(buff) ((buff)->n)

#define luaZ_buffremove(buff, i) ((buff)->n -= (i))
#define luaZ_resetbuffer(buff) ((buff)->n = 0)

#define luaZ_resizebuffer(L, buff, size) \
  ((buff)->buffer = luaM_reallocvchar(L, (buff)->buffer, (buff)->buffsize, size), (buff)->buffsize = size)

#define luaZ_freebuffer(L, buff) luaZ_resizebuffer(L, buff, 0)

LUAI_FUNC void luaZ_init(lua_State* L, ZIO* z, lua_Reader reader, void* data);
LUAI_FUNC size_t luaZ_read(ZIO* z, void* b, size_t n); /* read next n bytes */

/* --------- Private Part ------------------ */

struct Zio {
  size_t n; /* bytes still unread */
  const char* p; /* current position in buffer */
  lua_Reader reader; /* reader function */
  void* data; /* additional data */
  lua_State* L; /* Lua state (for reader) */
};

LUAI_FUNC int luaZ_fill(ZIO* z);

#endif
